Thanks for all the replies. My Rancher has 250km/157 miles on it, bought it late October 2020.
will leave the engine be until it needs a new top end. May look at swapping the clutch springs out. Which means buying more tools.
There was not one footshift 520 Foreman/Rubicon to be had anywhere. My dealer had 5 Ranchers left when I bought mine, im super happy with it.
when It needs a new top end, I will look more in to this.
Maybe add a turbo too.